Transient Logging on PCI-6133

[IGC]

I am using a PCI-6133 board and LabVIEW 8.2.   I'm using a 2MS/s rate and I need to capture a transient pulse, save 100 samples of six channels to file and return to ready state for the next pulse in less than 1mS.  I am using DAQmx VIs to set up a reference trigger on AI0 and the best I can achieve is about 10mS from trigger to trigger.  The Channel, Timing Clock and Trigger setup VIs take about 4mS, the Read VI takes 2mS and the Clear Task VI takes another 3mS.  I've tried using a Digital Trigger on PFI0 with no obvious improvement.

Am I doing something wrong, or is using the DAQmx VIs the wrong approach?

I would appreciate any help!

Cheers

IGC

[GarPar]

Hi IGC-

     DAQmx is the right approach, but you can set up your task differently.

     First off, there is no need to set the channel, timing, trigger, and clear the task between every trigger.  All you need inside the while loop is a DAQmx Read.

     To make a 'retrigerrable' analog input task using your 6133, you will need to create a retriggerable counter output task that acts as the sample clock for the analog input task.  The counter task can be configured to receive the trigger and output 100 pulses at 2 MHz.  The analog input then uses this counter output as the sample clock and gathers the 100 samples at 2 MHz.  Here is a link to a LabVIEW example that does exactly this task.

     All you need to do is insert your code that writes to file.

     I hope this helps.  Best of luck with your application!